Definitions of pass off
(INTELLECTUAL PROPERTY) to use a deceptive (=misleading) market practice, often involving trademarks, that causes a company's products or services to be confused with those of a competitor
We have a right to protect our distinctive colour purple from others seeking to pass off their products as Cadbury chocolate.
if you pass something off as something else then you pretend that it is another thing or another brand in order to cheat someone such as a customer or an official
He tried to pass his swimming certificate off as a masters degree from Cambridge.
to act in way to make something bad, important, or serious look less bad, important, or serious
He was humiliated by his boss but he passed it off as a joke.